Study Finds Diagnostic Delay, Less Intensive Therapy Use in PsA than RA

A recent nested matched cohort study indicated that patients with psoriatic arthritis (PsA) have a longer duration of symptoms before referral and a longer interval between presentation to a general practitioner and diagnosis than those with rheumatoid arthritis (RA).1

Previous research has indicated that, despite similar disease impact and physical function at diagnosis, patients with PsA had a longer delay to diagnosis. Additionally, patients with PsA are less likely to receive combination treatment and may have increased disease burden 3 months after presentation.2

“This study aimed to gain a greater understanding of delay to diagnosis and compare the time from general practitioner presentation to diagnosis, for patients with PsA with that of patients with RA,” wrote William Tillett, PhD, department of rheumatology, Royal National Hospital for Rheumatic Diseases, and colleagues. “The study also aimed to compare disease activity and impact of disease, as well as treatment initiation, including treat-to-treat and [disease-modifying antirheumatic drug (DMARD)] therapy, between the PsA and RA cohorts.”1

Tillett and colleagues utilized data collected for the 2018 British Society for Rheumatology National Early Inflammatory Arthritis Audit (NEIAA); included patients were ≥16 years and attending specialist Rheumatology Centres in England and Wales for suspected inflammatory arthritis for the first time. A total of 4240 patients were considered eligible: 2120 with RA and 2120 with PsA.1

Eligible patients with PsA were then randomly matched to an RA patient based on age and sex. Patients with a diagnosis of RA or inflammatory polyarthritis (affecting ≥5 joints) were eligible for follow-up, and patient-reported outcomes were collected at baseline and 3- and 12-month follow-up periods.1

The time between first symptoms and referral was compared between patients in each cohort: 40% of patients with RA and PsA were referred to a specialist within 3 working days (P = .145). However, patients with PsA experienced a longer duration of symptoms before referral and a longer duration between first presentation and receiving a diagnosis (P <.001). Once referral had been received by secondary care, there was another similar delay (adjusted hazard ratio [aHR], 0.87: 95% CI, 0.79-0.96, P <.007 and aHR, 0.86: 95% CI, 0.80-0.95, P <.002, respectively).1

Tillett and colleagues also noted that considerably fewer DMARDs were prescribed at baseline to patients with PsA compared with their matched RA comparators (54% and 69%, respectively; P <.001). These results were consistent at the 3-month follow-up, when percentages of those who had initiated DMARD rose to 73.9% and 87.5%, respectively (P <.001). Based on the collective DMARD initiation in the first 3 months, patients with PsA were found to be started more often on a single DMARD, while those with RA were started on multiple.1

Patient-reported outcomes were available for roughly 40% of patients at baseline and 20% at 3-month follow-up. A total of 502 patients with PsA and 505 patients with RA had completed the form at baseline, and 258 patients with PsA and 270 with RA at the follow-up. Restricting data to patients with both data sets indicated a greater improvement in the RA cohort than the PsA cohort.1

These data suggest that patients with PsA experienced longer delays in diagnosis, are less likely to receive DMARD therapy, and have little improvement during their first 3 months of care. According to investigators, however, much of this knowledge is nothing new. Instead, the team is leveraging the data to call for earlier diagnosis and treatment.1

“These findings highlight the need for education both of patients and the clinical team, to support earlier diagnosis and treatment, thus improving longer-term outcomes,” wrote Tillett and colleagues.1

References

1. Charlton RA, Gates E, Coates LC, et al. Diagnostic delay and less intensive therapy for people with psoriatic arthritis compared with rheumatoid arthritis: A study nested within an English and Welsh audit data set. Annals of the Rheumatic Diseases. Published online March 29, 2025. doi:10.1016/j.ard.2025.02.020

2. Holland R, Davis A, Green A, et al. FRI0514 psoriatic arthritis is associated with diagnostic delay and worse outcome at three months when compared to rheumatoid arthritis: Results from the UK national audit for inflammatory arthritis. Annals of the Rheumatic Diseases. 2017;76:685. doi:10.1136/annrheumdis-2017-eular.5066